I've a bunch of data stored in a mysql database as a bunch of unix style timestamps (in UTC). Previously, these have been formatted via Perl's gmtime(). It seems that MySQL's FROM_UNIXTIME() function tries to be helpful, and correct for daylight savings, but I really don't want it to.

Is there a nice handy method to convert the results from the system timezone (GMT/BST) to UTC or alternately determine if DST was in effect for a particular time?

This works great. Thank you Wrikken. I am just adding some code here for my reference so I don't forget when I search my favourites. set blahblah= convert_tz(from_unixtime(blahblah),@@session.time_zone,'+00:00');
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codingknobMay 16 '13 at 22:38

Would be apt for a case by case basis indeed, so depending on whether you need all date/time related fields to reflect another timezone, or just a single one, choose one or the other.
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WrikkenMay 16 '13 at 22:40